<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>示例22</title>
    <script>
        function Customer() {
            this.nickName = '小李';
        }
        // 使用箭头函数定义原型对象中的方法 
        Customer.prototype.show = () => {
            console.log(this.nickName);
        }
        var cust1 = new Customer();
        cust1.show(); // undefined 
    </script>
</head>

<body></body>

</html>